1. Field of the Invention
The present invention relates to an information processing apparatus, an information processing method, a program, and a computer readable recording medium having the program recorded therein for inferring a fundamental cause of abnormality.
2. Description of the Related Art
Conventionally, there is known an apparatus that infers a fundamental cause of abnormality (deficiency) such as a failure of manufacturing equipment using a so-called expert system. Even a user with a poor ability for inferring a fundamental cause is capable of quickly and accurately resetting equipment to a normal state by using such an apparatus.
However, with such an apparatus, the inferred fundamental cause is only notified to the user. The user cannot understand due to what kinds of reasons (through what kind of mechanism) the abnormality has occurred from the fundamental cause. In other words, the user cannot logically understand a reason that logically links the abnormality and the fundamental cause.
For example, Japanese Patent No. 3455276 (laid open Oct. 20, 1995) discloses a failure diagnosis apparatus that displays, when a fundamental cause can be inferred, an inference result (i.e., a search object indicating for which component or in which place inference is performed), an inspection result, and a cause of a phenomenon observed by the inspection to notify a user working as a service person of the inference result, the inspection result, and the cause of the phenomenon. The user is allowed to logically understand a link between a deficiency phenomenon and the inference result by using this failure diagnosis apparatus.
The abnormality is usually caused by stepwise accumulation of plural causes. In other words, for example, when it is assumed that a direct cause of the abnormality is a cause A, a phenomenon of the cause A is caused by a cause B that is a direct cause of the phenomenon and a phenomenon of the cause B is caused by a cause C (a fundamental cause) that is a direct cause of the phenomenon.
In a usual process of inference, a fundamental cause is inferred by selecting, at least at certain one stage, one cause out of two or more causes that cause a cause (a phenomenon) at the stage.
However, in the failure diagnosis apparatus disclosed in Japanese Patent No. 3455276, although the search object and the cause of the phenomenon observed in the inspection are displayed, it is not indicated what kinds of causes are accumulated stepwise in what kind of order to cause the abnormality. Moreover, a causal relation between a cause at a certain stage (hereinafter “high order cause”) and a direct cause of the cause (phenomenon) (hereinafter “low order cause”) (i.e., a reason why the high order cause occurs from the low order cause) is not displayed.
Therefore, with the conventional failure diagnosis apparatus, the user cannot understand what kinds of causes are accumulated stepwise in what kind of order to cause abnormality and due to what kinds of reasons the respective causes occur from direct causes of the respective causes.